typedef struct
{
LARGE_INTEGER StartingVcn;
} STARTING_VCN_INPUT_BUFFER, *PSTARTING_VCN_INPUT_BUFFER;

typedef struct RETRIEVAL_POINTERS_BUFFER
{
DWORD ExtentCount;
LARGE_INTEGER StartingVcn;
struct
{
LARGE_INTEGER NextVcn;
LARGE_INTEGER Lcn;
} Extents[1];
} RETRIEVAL_POINTERS_BUFFER, *PRETRIEVAL_POINTERS_BUFFER;


ULONGLONG *GetFileClusters(
PCHAR lpFileName,
ULONG ClusterSize,
ULONG *ClCount,
ULONG *FileSize
)
{
HANDLE hFile;
ULONG OutSize;
ULONG Bytes, Cls, CnCount, r;
ULONGLONG *Clusters = NULL;
BOOLEAN Result = FALSE;
LARGE_INTEGER PrevVCN, Lcn;
STARTING_VCN_INPUT_BUFFER InBuf;
PRETRIEVAL_POINTERS_BUFFER OutBuf;

hFile = CreateFile(lpFileName, FILE_READ_ATTRIBUTES,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
NULL, OPEN_EXISTING, 0, 0);

if (hFile != INVALID_HANDLE_VALUE)
{
*FileSize = GetFileSize(hFile, NULL);

OutSize = sizeof(RETRIEVAL_POINTERS_BUFFER) + (*FileSize / ClusterSize) * sizeof(OutBuf->Extents);

OutBuf = malloc(OutSize);

InBuf.StartingVcn.QuadPart = 0;

if (DeviceIoControl(hFile, FSCTL_GET_RETRIEVAL_POINTERS, &InBuf,
sizeof(InBuf), OutBuf, OutSize, &Bytes, NULL))
{
*ClCount = (*FileSize + ClusterSize - 1) / ClusterSize;

Clusters = malloc(*ClCount * sizeof(ULONGLONG));

PrevVCN = OutBuf->StartingVcn;

for (r = 0, Cls = 0; r < OutBuf->ExtentCount; r++)
{
Lcn = OutBuf->Extents[r].Lcn;

for (CnCount = OutBuf->Extents[r].NextVcn.QuadPart - PrevVCN.QuadPart;
CnCount; CnCount--, Cls++, Lcn.QuadPart++) Clusters[Cls] = Lcn.QuadPart;

PrevVCN = OutBuf->Extents[r].NextVcn;
}
}

free(OutBuf);

CloseHandle(hFile);
}
return Clusters;
}

Взято из статьи 3 метода работы с занятыми файлами
https://vxlab.info/wasm/article.php-article=lockfileswork.htm
Заранее огромное спасибо

Взято из статьи 3 метода работы с занятыми файлами
https://vxlab.info/wasm/article.php-article=lockfileswork.htm
Заранее огромное спасибо